Method for threading the leading end of a weblike material



3,127,079 MATERIAL March 31, 1964 c. ALLANDER METHOD FOR THREADING THELEADING END OF A WEBLIKE AND A DEVICE FOR CARRYING OUT THE METHOD 1962 3Sheets-Sheet 1 Filed Feb. 6,

FIG. I.

INVENTOR! CLAES ALLANDER ATTYS.

March 31, 1964 c, ALLANDER 3,127,079

METHOD FOR THREADING THE LEADING END OF A WEBLIKE MATERIAL AND A DEVICEFOR CARRYING OUT THE METHOD Filed Feb. 6, 1962 3 Sheets-Sheet 2 mvsmon:CLAES ALLANDER AT TYS.

FIG4.

FIGB

3 Sheets-Sheet 3 INVENTOR. CLAES ALLANDER WWW ATTYS.

METHOD FOR THREADING THE LEADING END OF A WEBLIKE MATERIAL AND A DEVICEFOR CARRYING OUT THE METHOD Filed Feb. 6, 1962 F IG. 6.

FIGS

United States Patent 3,127,079 METHOD FOR THREADING THE LEADING END OF AWEBLIKE MATERIAL AND A DEVICE FOR QARRYING GUT THE METHQD (IlaesAllander, Bromma, Sweden, assignor to Aktieholaget SvenskaFlaktfahriken, Stockholm, Sweden Filed Feb. 6, 1962, Ser. No. 171,794Claims priority, application Sweden Feb. 8, 1961 Claims. (Cl. Hit-92)The present invention relates to a method and a device adapted for socalled threading, i.e. guiding and advancing the leading end of aweblike, preferably wet material with low mechanical strength, whichmaterial is to be advanced in one or more passages through a dryingplant between turning rolls mounted at the ends of said passages. Whentreating a weblike material in apparatus of the aforesaid type, it hasalways proved difiicult to guide and advance the leading end of the webmaterial. It was heretofore common practice to transfer the leading endof the web at the turning points of the web to the different conveyingelements of the various passages by hand. This method-besides being timewastingis particularly troublesome when applied to wet material of lowmechanical strength, for example cellulose pulp. The reduction in speednecessitated by the said manual threading requires, moreover, in thetreatment of cellulose pulp the application of a certain complicatedadjusting work with the preceding wet section. The aforesaiddifficulties arising in connection with the threading of the leading endhave increased still more since the introduction of more modern plants.In View of the fact that such modern plants operate without mechanicalconveyors, the web being advanced entirely air-borne, it is necessary toguide the leading end of the Web in a mechanical manner continuouslyalong all its way of conveyance and not, as before, only at the turningpoints. For reasons of space, the runs of the web have to be spacedrelative one another in such a manner that a manual mechanical controlof the leading end between the turning points is rendered impossible.

The present invention relates to a novel method for threading theleading end of a web and is characterized in that the leading end of thematerial web is maintained stretched in the direction of conveyance ofthe web and prevented from fluttering by being connected to a guidingmember introduced into the machine prior to the feeding of the materialweb, said guiding member being preferably a thin, flexible, resilientstrip, for example steel strip, inserted in a guide rail extending alongthe side of the entire conveyance path of the web and substantiallyenclosing said guiding member entirely, the said guide rail beingprovided with a narrow slot facing the web, and in that said guidingmember is advanced by being pressed against the turning rolls or againstseparate support rolls which are driven during the threading operationby means of rollers provided in recesses in the guide rail.

The device according to the invention comprises a guiding member of theaforedescribed type with associated guide rail and coupling means forconnecting the guiding member with the leading end of the material web,and is characterized in that said coupling means comprise a holderprojecting through said guide rail slot and adapted to be hooked in therear end portion of said guiding member, said holder being connected bya wire with a V-shaped folded gripping band, the legs of which aremaintained pressed against one another by inserted spring means, and inthat the guiding member as well as the coupling means prior to thethreading are kept in a ready-for-operation position in front of thedrying plant, a guide means for said gripping band being di- "ice rectedobliquely towards the edge of the material web and provided with aV-shaped bar for parting the legs of the gripping band when the grippingband is being introduced and maintaining the legs in parted positionuntil-after having passed said barthe legs are released and grip theedge of the material web. In a preferred embodiment of the deviceaccording to the invention both ends of the guiding member have athickness exceeding the width of the guide rail slot and are so designedthat the holder of the gripping band may be hooked in at both said ends.

The invention will now be described more in detail with reference to theaccompanying drawings showing by Way of an example an embodiment of thedevice according to the invention.

FIG. 1 is a plan view of apparatus embodying the invention;

FIG. 2 is a vertical longitudinal section through the apparatus shown inFIG. 1;

FIG. 3 is an enlarged partial section of parts shown near the top ofFIG. 2;

FIG. 4 is a top plan view of parts shown in FIG. 3;

FIG, 5 is an enlarged section taken on the line 5-5 of FIG. 3;

FIG. 6 is an enlarged section taken on the line 6-6 of FIG. 3;

FIG. 7 is a plan view of the flexible connecting strip;

FIG. 8 is a side elevation of the strip shown in FIG. 7; and

FIG. 9 is an exploded perspective view showing the couplingconstruction.

In the accompanying drawings 1 designates a drying plant or the like forweblike material 2 which is to be advanced through said plant in aplurality of horizontal windings between turning rolls 3 located at bothends. According to the invention, a guiding member is used for guidingthe leading end 2a of the web 2 through said plant, which guiding memberconsists of a thin, flexible, resilient strip 4. The strip is introducedinto a guide rail 5 extending along the side of the entire conveyancepath of the web and substantially enclosing said guiding member 4entirely. Said guide rail 5 is provided with a narrow slot 5a facing theweb. Rollers for feeding the guiding member are designated 6, saidrollers being arranged in recesses 7 in the guide rail 5 and pressingthe guiding member 4 against the turning rolls 3 or against separatesupport rolls 8 which are driven during the threading operation. 9designates springs mounted on the rollers 6. In the embodiment shown theguiding member is folded at both ends 4a and 412 respectively andprovided with a recess 1% for hooking therein a holder 11 projectingthrough the said guide rail slot 5a. The said holder 11 is connectedwith a V-shaped gripping band 13 via a wire 12. Such an edge-grippingband is disclosed in the copending application of Allander et al., S.N.836,221, filed August 26, 1959, now Patent No. 3,085,346. The legs ofsaid gripping band are in known manner maintained pressed against oneanother by inherent resilience or by inserted spring means. Said guidingmember 4 and the coupling means are, prior to the threading of theleading end, arranged in a ready for operation position in front of theplant in an arrangement (not shown). Said arrangement should comprisemeans for parting the legs of the gripping band when the gripping bandis being introduced and maintaining said legs in parted positionuntilafter having passed said parting means-they are released and gripthe edge of the material web, all as disclosed in said copendingapplication. 14, 15 and 16 designate driving means for the turning rolls3 and support rolls 8. The profile and dimensions of the guiding member4 and guide rail 5 may be varied within the scope of the inventionaccording to specific requirements.

What I claim is:

1. Apparatus for threading the leading end of a web through dryingapparatus having a plurality of web supporting rolls at the ends ofweb-drying passages, comprising in combination, a continuous tubularguide rail arranged at at least one end of said rolls and following theweb path between and around said rolls, said tubular guide rail having acontinuous slot on the side toward the web path, a flexible resilientleader strip movable along the tubular space of said guide rail,connecting means between said leader strip and an edge of said web,including means extending through the slot of said rail, and power drivemeans engaging said leader strip to feed it through the tubular guiderail.

2. Apparatus as set forth in claim 1, in which said connecting meansincludes a member having a hook connection with said leader strip whichis movable through said tubular rail and having a lateral portionextending through said slot and connected to an edge of said web.

3. Apparatus as set forth in claim 2, in which said leader strip isprovided with end portions having a thickness greater than the width ofsaid guide rail slot, said end portions being provided with meanscomprising part of hook connection of said Web connecting means.

4. Apparatus as set forth in claim 1, in which said power drive meansincludes roll means at the ends of said web supporting rolls engagingthe leader strip on both sides to grip and drive it.

5. Apparatus as set forth in claim 4, in which said roll means includesdriven supporting rolls and resiliently biased pressure rolls engagingthe leader strip.

References Cited in the file of this patent UNITED STATES PATENTS1,700,099 Shively Jan. 22, 1929 2,792,185 Julliard May 14, 19572,812,937 Robinson Nov. 12, 1957 2,944,345 Faeber July 12, 1960 FOREIGNPATENTS 1,229,320 France Sept. 6, 1960

1. APPARATUS FOR THREADING THE LEADING END OF A WEB THROUGH DRYINGAPPARATUS HAVING A PLURALITY OF WEB SUPPORTING ROLLS AT THE ENDS OFWEB-DRYING PASSAGES, COMPRISING IN COMBINATION, A CONTINOUS TUBULARGUIDE RAIL ARRANGED AT AT LEAST ONE END OF SAID ROLLS AND FOLLOWING THEWEB PATH BETWEEN AND AROUND SAID ROLLS, SAID TUBULAR GUIDE RAIL HAVING ACONTINOUS SLOT ON THE SIDE TOWARD THE WEB PATH, A FLEXIBLE RESILIENTLEADER STRIP MOVABLE ALONG THE TUBULAR SPACE OF SAID GUIDE RAIL,CONNECTING MEANS BETWEEN SAID LEADER STRIP AND AN EDGE OF SAID WEB,INCLUDING MEANS EXTENDING THROUGH THE SLOT OF SAID RAIL, AND POWER DRIVEMEANS ENGAGING SAID LEADER STRIP TO FEED IT THROUGH THE TUBULAR GUIDERAIL.